This study compares four different anesthesia induction regimens to see which one provides the most stable blood pressure and heart rate during rapid sequence intubation. A total of 172 patients undergoing elective surgery will receive one of four combinations of propofol and opioids (alfentanil or sufentanil). The main outcomes are hypotension (low blood pressure), inadequate blunting of the stress response to intubation, and intubating conditions. The study aims to determine whether a lower dose of propofol combined with a higher dose of alfentanil can improve hemodynamic stability without compromising the quality of tracheal intubation.